In recent years, motion-assist devices have been developed, separately from autonomous robots. A motion-assist device is wearable by a human body for assisting human activity of the human body. The motion-assist device assists the motion of the wearer. The assistance is implemented by acquiring bioelectrical signals (biological information including, for example, myoelectric potential signals, neurotransmission signals, and brain wave detection signals) of the wearer, and supplying power in accordance with the intention of the wearer, to an actuator of the motion-assist device, based on the acquired bioelectrical signals. Meanwhile, it is known that doctors and physical therapists conduct rehabilitation for patients who cannot move their bodies due to factors such as age, cerebral apoplexy and spinal cord injury, for the purpose of recovering muscle strength and preventing muscle strength from declining.